Means for simultaneous drying and grinding



Feb. 19, 19219. 1,702,333

E. BARTHELMESS [BANS FOR SIIULTANEQUS DRYING AND GRINDING Filed lay 15,1926 Patented Feb. 19, 1929.

UNITED STATES PATENT OFFICE.

HEARS FOR SIMULTANEOUS DRYING AND GRINDING.

Application filed Kay 15, 1926, Serial No. 109,345, and in Germany Kay15, 1925.

Ordinary methods of simultaneous grinding and drying of materials, havethe disadvantage that the bearings and other elements of the grinder areexposed to the high temperature of the drying fluid and detrimentallyaffected thereby.

The object of the present invention is to obviate this disadvantage byapplying the drying process to a grin ing apparatus wherein thematerials are fed into a sitter which returns them through a grinder tothe feeding conduit until suflicicntly ground, and the inventionconsists in applying the drying fluid to the feeding conduit so that thereturn 5 conduit through the grinder will remain unaffected by thefluid.

The drying fluid may be used as a means for driving the materialsthrough the apparatus.

Fig. 1 of the accompanying drawings represents a diagrammatic view of agrinding and drying apparatus according to the invention, and

Fig. 2 is a diagram of a modified arrangement.

In both arrangements there is a feeding conduit f which leads. from afeeding device a, up into a wind sifter 10. From the latter a conduitleads to a fan 6 which draws the materials from the feeding device a upinto the sifter. Insuiiiciently ground materials are rturned by thesifter through conduits r and 'v and through a grinder m to the feedingconduit, while the finer materials pass through the fan and aredelivered by the latter into a separator c where they are divided offfrom the air.

According to the invention the drying of the materials is effected inthe feeding conduit 7. and the grinder, which is not exposed to the 40drying fluid, will thus only receive surface dried materials which, inbreaking up, present fresh, moist surfaces for exposure to the dryingfluid in the conduit 7. In this manner the materials keep on circulatinguntil theydare sufficiently ground and sufficiently drie The fluid which'drives the materials through the conduits may also be used for thedryin of the same for which purpose it is so passe through a heater hbefore it enters the feeding duct f. In the arrangement accordmg to Fig.1 the moisture-laden fluid is i is discharged through a flue I), whilethe dried and ground materials are discharged at the bottom of theseparator c.

Inthearrangement according to Fig. 2, the fluid is led from theseparator 0 to a condenser k where it is cooled for the liberatlon ofthe fluid from its moisture. Cooling water enters the condenser at z andleaves itat u. The water of condensation leaves the condenser at 8,while the dry air or gas is said pipe to the sifter, means for treatingthe materials with a dr ing fluid on their way to the sifter, a grin er,means for feeding the coarse materials from the sifter into the grinder,and means for feeding the materials from the grinder into said feedpipe.

3. A drying and grinding apparatus comprising a sitter, a feed pipeleading to said sifter, means for feeding materials, into said pipe,means for feeding a fluid through said pipe so as to carry the materialsto the sifter, means for heating the fluid, a grinder, means for feedingthe coarse materials from said sitter into the grinder, and means forfeeding the materials from the grinder into said feed ipe. p 4. Thestructure claimed in claim 3 in combination with a condenser, means forfeeding the fluid from the sifter into said condenser, and means forleading the fluid from the con denser back to the feed pipe.

5. A drying and grinding apparatus comprising a -pipev circuit, a fan insaid circuit for driving materials through the same by means of a fluid,a heater arranged in the circuit for heating said fluid, means forfeeding materials into the pipe circuit behind the heater, a wind sifterarranged in the circuit 7 between the feeding device and the fan, a. 5grinder arranged outside the circuit so as to receive materials from thesifter and return them to the circuit, a. separator arranged separatorfor clearing the fluid of moisture before it is returned to the heater.

EMIL BARTHELMESS.

